Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f50171430690158…

MALICIOUS

PDF

87.9 KB Created: 2021-07-24 16:50:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 81fd7de9fadcc447c133b7c5e6538ef2 SHA-1: 25163ba4fca8fc9e4b4ac63f72493d437b5ee8b5 SHA-256: 5f50171430690158ced7edc1413ac77abf7eb9d260c0d50c1e756bf2e7b23887
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1055.012 Process Injection

The PDF contains numerous links, many of which point to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to distribute malicious content or engage in SEO manipulation. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://gadd-asso.org/userfiles/file/49500456573.pdf In PDF document text
    • http://stressmanagement-karriere.de/userfiles/file/88138808647.pdfIn PDF document text
    • http://chikatere.com/Upload/files/lesetinuxenunonezaporowib.pdfIn PDF document text
    • http://detikakdeti.ru/img/file/tinufadeki.pdfIn PDF document text
    • http://xn--zb0bw3kv4s8mn.com/upload/fckeditor/file/73926575579.pdfIn PDF document text
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/252p9bc1gc30tdnebgoft0hc41/koxepikevadesor.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/todogifuvexanopesalorapex.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0bea3b89dd---jilulilowegonijanab.pdfIn PDF document text
    • http://capitaldanceacademy.com/userfiles/files/junuzawokaxajomu.pdfIn PDF document text
    • http://easytravel63.ru/ckfinder/userfiles/files/78428219717.pdfIn PDF document text
    • http://bioident.pl/photos_fck/file/fubideguwa.pdfIn PDF document text
    • https://socialacademy.gr/wp-content/plugins/super-forms/uploads/php/files/c40cb7cf8798117b068f3fddbec5f318/xezitagunopezokab.pdfIn PDF document text
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/d74199aa2d9f69d1e4ab5efffea154b8/nudiwivusemeso.pdfIn PDF document text
    • http://cariboohose.com/userfiles/file/48468133538.pdfIn PDF document text
    • https://turbooto.vn/upload/files/suwevipavefup.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16073ad8f09419---68546542122.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf909ec021a---16936506660.pdfIn PDF document text
    • https://fasaac.org/temp//files/lumumidepav.pdfIn PDF document text
    • http://chongros.com/userData/board/file/nirexufalazilazalalesikop.pdfIn PDF document text
    • http://ecompletecontact.com/ckfinder/userfiles/files/80658112061.pdfIn PDF document text
    • http://hasici-pristroje-eshop.cz/files/file/33605449105.pdfIn PDF document text
    • http://zulassung4you.de/bilder/file/budubirer.pdfIn PDF document text
    • http://abnicum.com/files/file/zevamixotikisitebobolog.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=beginners+gluten+free+food+list+printablePDF link annotation
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/df1e9bc7cadf3de185adbcb9b2aa17b7/4854857756.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f40a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF40A 17140 bytes
SHA-256: ac10ae7d6fd80058060f5b6b001668e99ef1ed7c2680341b0cb3a458ad941c7b
font_01_sfnt_off0001208e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1208E 10968 bytes
SHA-256: bfea204c87191cd18daf8ec6634faa86633d5f55d7599dbfae4dbcba4c60ddc7
font_02_sfnt_off000139b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139B4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1